新型希土4-羟基-7-三氟甲基-3-喹啉基甲酸乙酯配合物的光物理性质(英文)

首次合成了五种新型希土（Ｅｕ３＋，Ｔｂ３＋，Ｇｄ３＋，Ｓｍ３＋，Ｄｙ３＋）配合物。配体为带有喹啉环的４羟基７三氟甲基３喹啉基甲酸乙酯。并用元素分析、红外光谱和热分析方法确定了配合物的组成。通过测定钆配合物的低温磷光光谱表明４羟基７三氟甲基３喹啉基甲酸乙酯的三重态能级为２２０００ｃｍ－１。配合物的光物理性质表明配体的三重态能级适于希土Ｅｕ３＋，Ｓｍ３＋，Ｄｙ３＋和Ｔｂ３＋，特别是Ｔｂ３＋的发光。

钇与2-(4′-氯-2′-膦酰基一苯偶氮)-7-(2′,6′-二溴-4′-氯-一苯偶氮)-1,8-二羟基-3,6-萘二磺酸配位反应动力学研究和机理探讨

用停流分光光度法获得反应的经验速率方程为R=k[y(H_2O^n)^(3+)]·[H_6R]·[H^+]^(-1)。参考Eigen-Tamm机理和测得的动力学参数,拟出了反应的可能机理。

Luminescence Properties of Sm^(3+) doped Bi_2ZnB_2O_7

The phosphors of （Bi1- x Smx ） 2ZnB2O7 （ x = 0. 01, 0. 03, 0. 05, 0. 07, and 0. 09） were synthesized by conventional solid state reaction. The purity of all samples was checked by X-ray powder diffraction （XRD）. XRD analysis shows that all these compounds are of a single phase of Bi2ZnB2O7, indicating that the Bi^3＋ in Bi2ZnB2O7 can be partly replaced by the Sm^3＋ without the change of crystal structure. The excitation and emission spectra at room temperature show the typical 4f-4f transitions of Sm^3＋ . The dominant excitation line is around 404 nm due to ^6H5/2→^4K11/2 and the emission spectrum consists of a series of lines at 563, 599, 646, and 704 nm due to ^4G5/2→^6H5/2, ^6H7/2, ^6H9/2, and ^6H11/2, respectively. The optimal concentration of Sm^3＋ in Bi2ZnB2O7 is about 3mol% （relative to lmol Bi^3＋ ） and the critical distance Rc was calculated as 2.1 nm. The temperature dependence of the emission intensity of Bi1.94Sm0.06ZnB2O7 was examined in the temperature range between 100 and 450 K. The quenching temperature where the intensity has dropped to half of the initial intensity is 280 K. The lifetime for Sm^3＋ in Bi1.94Sm0.06ZnB2O7 is fitted as a value of 0.29 and 1.03 ms.

Sol-gel processed Ce^(3+), Tb^(3+) codoped white emitting phosphors in Sr_2Al_2SiO_7

Sr2Al2SiO7：Ce^3＋, Tb^3＋ white emitting phosphors were fabricated using the sol-gel method. X-Ray Powder Diffraction （XRD） analysis confirmed the formation of Sr2Al2SiO7：Ce^3＋, Tb^3＋. Scanning Electron Microscopy （SEM） observation indicated that the microstructure of the phosphor consisted of regular fine grains with an average size of about 0.5-1 μm. Luminescence properties were analyzed by measuring the photoluminescence spectra. The Ce^3＋, Tb^3＋-codoped Sr2Al2SiO7 phosphors showed four main emission peaks： one at 414 nm for Ce^3＋ and three at 482, 543, and 588 nm for Tb^3＋. The emission spectra of the samples with different doping concentrations showed that the Tb^3＋ emission was dominant because of the persistent energy transfer from Ce^3＋. The decay characteristic was better than that prepared by the solid-state process in the comparable condition. The codoped phosphor displayed long persistent white phosphorescence.

Influence of annealing temperature on luminescent properties of Eu^(3+)/V^(5+) co-doped nanocrystalline Gd_2Ti_2O_7 powders

Nanosized Gd2(1–x)Eu2xTi2O7:yV5+ phosphors were prepared via sol-gel method and characterized with X-ray diffraction,Raman spectroscopy,diffuse reflectance spectra and photoluminescence spectra.Their PL properties were investigated as functions of the Eu3+ doping concentration and annealing temperature.The results indicated that the as-prepared samples showed a strong emission of Eu3+ under the irradiation of 303 nm.For Eu3+-doped Gd2Ti2O7,the orange emission at 586 nm was the strongest,which was correspond...

Photoluminescence of SrGdGa_3O_7∶RE (RE=Ce^(3+), Pr^(3+), Tb^(3+)) under VUV-UV Excitation

SrGdGa3O7∶RE (RE=Ce3+, Pr3+, Tb3+) were prepared by traditional solid-state reaction and their luminescence properties in the range of VUV-Vis were investigated. The two broad bands situated at about 177 and 217 nm in excitation spectra are attributed to the host lattices absorption, and they have no considerable change when doped different rare earth ions. The f-d transitions of Pr3+ and Tb3+ calculated by the formula gathered by Dorenbos were compared to the experimental results. The excitation spectra also show the sharp Gd3+ excitation line at about 274 nm pointing to an efficient energy transfer from Gd3+ to Pr3+ and Tb3+. All of the emission spectra present the characteristic emissions of rare earth ions when excited by VUV and UV.

A New Co-Activator Gd_2O_3 to Eu_2O_3 and Dy_2O_3 Doped Alkaline Earth Silicate Phosphors

Three alkaline earth silicate phosphors: Sr2MgSi2O7∶Eu, Dy, Gd, Sr3MgSi2O8∶Eu, Dy, Gd and Sr2MgSi2O7∶Eu, Dy were prepared and their luminescent properties were investigated. The Photoluminescence (PL) measurements indicated that the phosphors gave a longer emitting phosphorescence phenomenon by comparing with those without Gd2O3 activator, in which a better afterglow characteristic was observed by adding Gd2O3 to the phosphors. While little influence on the structure of luminescent materials was observed via XRD spectra, and obvious emission wavelength shift was exhibited due to the differences in the structure parameters of the two hosts. The results revealed that the improvement was due to nonequivalent substitution to produce more e-traps, and energy transfer from Gd3+ to Dy3+, to boost the performance of Sr2MgSi2O7∶Eu, Dy phosphor. Role of Gd3+ co-doped into Sr2MgSi2O7∶Eu, Dy matrix and the possible long-lasting phosphorescence progress were discussed.

废旧轮胎颗粒二灰土与3∶7灰土的工程性能对比研究

本文利用室内固结试验和直剪试验,通过对比分析废旧轮胎颗粒二灰土和3∶7灰土的密度特性、强度特性、变形特性和湿陷特性,研究探讨了废旧轮胎颗粒二灰土处理湿陷性黄土的工程性能。研究结果表明:随着龄期的增长,废旧轮胎颗粒二灰土的剪切强度不断增加。废旧轮胎颗粒二灰土质量轻,强度较高,变形较小,建议在湿陷性黄土地基处理中推广应用。这不仅解决了废旧轮胎固体废弃物的环境问题,而且为湿陷性黄土地区地基处理的工程实践提供了新思路和新方法。

1∶12型Tb(Fe_(1-x)Co_x)_(11.3)Nb_(0.7)化合物的结构和磁性

通过ｘ射线衍射和磁性测量，研究了１∶１２型稀土过渡族金属间化合物Ｔｂ（Ｆｅ１－ｘＣｏｘ）１１．３Ｎｂ０．７的结构和磁性，其中ｘ＝０．００、０．０５、０．１０、０．１５、０．２０和０．３０．实验结果表明所有化合物均是四方ＴｈＭｎ１２型结构．晶格常数ａ、ｃ以及晶胞体积Ｖ随Ｃｏ含量增加而减小；Ｃｏ替代部分Ｆｅ后导致Ｔｂ（Ｆｅ１－ｘＣｏｘ）１１．３Ｎｂ０．７化合物的居里温度ＴＣ显著增加，而自旋重取向温度ＴＳＲ单调降低。

A_(7)M^(Ⅱ)RE_(2)(B_(5)O_(10))_(3)系列紫外非线性光学晶体的研究进展

稀土硼酸盐非线性光学(NLO)材料由于其在激光技术领域的重要应用而备受关注,这主要是因为三价稀土离子如Y^(3+)、Sc^(3+)、Lu^(3+)等可以有效抑制d-d和f-f电子跃迁从而扩宽化合物的透过范围,同时稀土原子与氧原子结合成畸变的多面体可增强材料的非线性光学效应。A_(7)M^(Ⅱ)RE_(2)(B_(5)O_(10))_(3)系列(RE为稀土金属,A为碱金属、M为二价金属)化合物是稀土硼酸盐中一类重要的材料,其A、M以及RE位点具备灵活的占据方式,近年来得到了广泛关注。通过化学元素取代法,研究者们对该类化合物的种类进行拓展,目前已经合成出数十种属于该体系的化合物。这些化合物的截止边大多处在紫外甚至是波长小于200 nm的深紫外波段,非线性光学效应为0.4~2.1倍KDP,在紫外以及深紫外波段非线性光学领域中展现出了应用潜力。本文对其研究现状进行了总结,分析了其微观结构与光学性能之间的关系,并指出不同位点组分对材料非线性光学性能的影响,以期对此类化合物今后的发展提供参考。

Up-Conversion Properties in KGd_2F_7∶Yb^(3+)/Tm ^(3+)

The infrared to visible up-conversion emissions in Yb 3+-Tm 3+ co-doped KGd_2F_7 samples excited at 980 nm was reported. The observed up-conversion emissions include intense blue 1G_4→3H_6 (482 nm) transition and other weak transitions: 1D_2→3H_6 (367 nm), 1G_4→3F_4 (651 nm) and 1G_4→3H_5 (776 nm). The concentration quenching of Tm 3+ or Yb 3+ is obvious at higher concentration due to the cross-relaxation. The optimum doping levels are 10% Yb 3+ and 0.2%～0.4% Tm 3+ for blue emission. Power studies reveal that the blue emission of Tm 3+ ion results from three-photon processes, which require three energy transfers from Yb 3+ to excite Tm 3+ from 3H_6 to 1G_4 in succession.

Vibrational Spectrum and Luminescence Properties of CaAl_(2)B_(2)O_(7)Eu^(3+)

The vibrational spectrum of the CaAl2B2O7 was investigated. It was shown that the vibrations of the BO3 groups are present in the region of 1400600 cm-1, and the bands at 519 nm-1 may originate from the AlO6 vibration. The luminescence properties of Eu3+ in CaAl2B2O7 were investigated. It was found that the Eu3+ ion in CaAl2B2O7 occupies two different sites. Investigation on the phonon sideband of Eu3+ indicates that BO3 groups are present in the surroundings of Eu3+ ions.

Heat Treatment of Nd_(1+x)Ba_(2-x)Cu_3O_(7-δ) Superconductors

Two kinds of Nd 1+ x Ba 2- x Cu 3O 7- δ , the sintered samples and zone melted samples, were treated in pure Ar at 950 ℃. The substitution of Nd ions for Ba ions in the Nd 1+ x Ba 2- x Cu 3O 7- δ before and after the heat treatment was investigated by XRD. In order to know the effects of heat treatment, the T c and J c of samples with and without the heat treatment in Ar were comparatively studied. The results show that the substitution of Nd for Ba decreases, whereas T c and J c increase after the treatment. The Nd 1+ x Ba 2- x Cu 3O 7- δ samples were oxygenated in pure oxygen at 300 ℃ . Based on the XRD spectra it was found that the samples with x <0.4 can transform from tetragonal phase into orthorhombic phase after the oxygenation, whereas in the sample with x >0.4 no phase transition occurs even after a long time oxygenation.

Conductivity of (NH4)3[CrMo6O24H6]·7H2O Treated by Nd Chemistry-Heated Diffused Permeation

Rare earth co-permeation of （NH4）3[CrMo6O24H6]·7H2O was reported and the conductivity of （NH4）3[CrMo6O24H6] was improved by 6.734×10^9 times. X-ray fluorescence spectrometry （XRF）, thermogravimetry-differential thermal analysis （TG-DTA）, X-ray diffraction （XRD） have been used to character （NH4）3[CrMo6O24H6]·7H2O and permeated sample. Experimental results showed that Nd could be permeated into the body of this sample and the XRD patterns showed great difference between （NH4）3[CrMo6O24H6]·7H2O and permeated sample. The structure of （NH4）3[CrMo6O24H6]·7H2O was destroyed and new compound MoN perhaps formed.

Synthesis,structure,and luminescence properties of melilite Dy^(3+):Lu_(x)CaLa_(0.98-x)Ga_(3)O_(7) phosphors for use in yellow light-emitting devices

Dy^(3+) and Lu^(3+) co-doped CaLaGa_(3)O_(7) phosphors were prepared via high-temperature solid-phase reaction.The electronic structures of LuxCaLa_(0.98-x)Ga_(3)O_(7) were investigated by the first-principles calculations.The influence of Lu^(3+) on yellow light emission was studied using X-ray diffraction(XRD)and photoluminescence(PL) measurements.The XRD results indicate that compared to Dy^(3+):CaLaGa_(3)O_(7),the cell parameters of Dy^(3+):LuCaLaGa_(3)O_(7) tend to decrease,which is due to the smaller radius of Lu^(3+).When pumped by blue GaN laser diode(LD),the emission peaks of phosphors with different Lu^(3+)doping concentrations in the visible region are similar,with the strongest peak at 574 nm in the yellow light region,which is sensitive to human eyes.The optimal doping concentration of Lu^(3+) is confirmed to be1 at%,when all emission spectra and measured fluorescence lifetimes are taken into account.Moreover,the optimal phosphor composition Dy^(3+):Lu_(x)CaLa_(0.98-x)Ga_(3)O_(7)(x=0.01) has an internal quantum efficiency(IQE) of 46.94% and an external quantum efficiency(EQE) of 15.19%.Most notably,the prepared phosphor demonstrates excellent thermal stability and a high activation energy(0.203 eV).In addition,the International Illumination Commission color coordinates of the Dy^(3+):LuxCaLa_(0.98-x)Ga_(3)O_(7) phosphors are in the yellow light area.The above analysis indicates that the Dy^(3+):LuxCaLa_(0.98-x)Ga_(3)O_(7)(x=0.001)phosphor has promising application prospects in yellow light-emitting devices.

Synthesis and optical properties of highly efficient Na_(3)KMg_(7)(PO_(4))_(6):Eu^(2+)blue phosphor for full-spectrum white-light-emitting diodes:The role of Li_(2)CO_(3)flux

Full-spectrum phosphor-converted white-light-emitting diodes(pc-WLED)are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a 400 nm NUV diode chip is still lacking.Herein,we present a blue-emitting Na_(3)KMg_(7)(PO_(4))6:Eu^(2+)phosphor synthesized by the solid-reaction method.Particularly,we find that the using of Li_(2)CO_(3)as flux can significantly improve the crystal quality and thus the emission efficiency of the phosphor.Meanwhile,the excitation peak of the phosphor shifts from 365 to 400 nm,which is pivotal for efficient NUV(400 nm)diode chip excitation.The practical Eu^(2+)concentration is also enhanced by using Li_(2)CO_(3)as flux,and the absorption efficiency is greatly increased.This phosphor exhibits superior PL thermal stability,namely retains 94%integrated photoluminescence intensity at 150℃of that at 25℃.As a result,the optimized phosphor shows an emission band peaked at 437 nm with a bandwidth of 40 nm and a high external photoluminescence quantum yield of 51.7%.Finally,a pc-WLED was fabricated by using NKMPO:Eu^(2+)blue,Sr_(2)SiO_(4):Eu^(2+)green,CaAlSiN_(3):Eu^(2+)red phosphors,and a 400 nm NUV diode chip.It shows a high color rendering index of R_(a)=96.4 and a correlated color temperature of 4358 K.These results prove that NKMPO:Eu^(2+)is a promising blue phosphor for full-spectrum WLED based on NUV diode chips.

高层建筑岩土工程勘察及不良地基处理措施分析

本文将围绕高层建筑岩土工程勘察作业开展分析讨论,包括钻探、原位测试、土体评价等技术手段,并结合勘察结果,为后续的不良地基处理提供数据支撑。以某城市的建筑为例,提出以换填三七灰土以及CFG桩(水泥粉煤灰碎石桩)加固为主的应对措施,最终发现此类加固手段能够切实提高地基承载力,实现荷载的均匀传递,确保工程的安全作业。

Low temperature heat capacities and thermodynamic properties of rare earth triisothiocyanate hydrates——Pr(NCS)_3· 7H_2O and Nd(NCS)_3· 7H_2O

Heat capacities of Pr(NCS)3·7H2O and Nd(NCS)3· 7H2O haw been measured from 13 to 300 K by using a fully automated adiabatic calorimeter. Schottky anomaly was observed for Pr(NCS)3·7H2O below 50 K. The polynomial equations for calculating the heat capacity values of the two compounds in the range of 13-300 K were obtained by the least-squares fitting based on the experimental Cp data. The Cp values below 13 K were estimated by using the Debye-Einstein and Schottky heat capacity functions. The standard molar thermodynamic functions were computed from 0 to 300 K. The standard entropies and Gibbs energies of formation of the two compounds were also calculated.

反相流动注射分光光度法测定稀土铝合金中的稀土总量

本文以二溴—氯偶氮氯磷作显色剂,建立了反相流动注射分析测定稀土总量的方法.实验表明,本方法简便,快速,且钙、铁的允许量较手工法约提高一个数量级.方法用于稀土铝合金中的稀土总量的测定,结果满意.

混合配体与稀土三元配合物的研究(Ⅱ)——γ酸(H_2γ)、邻菲咯啉(phen)与稀土(RE)三元配合物的合成及性质

本文报道了Υ酸(7—氨基—1—萘酚—3—磺酸,简称H_2Υ)、邻菲咯啉(phen)的9种稀土(RE)三元固体配合物的制备方法,通过化学和元素分析确定了它们的化学组成,并测定了三元配合物的摩尔电导、磁化率;还用红外光谱、紫外光谱、核磁共振谱、热谱及 x 射线粉末衍射进行了研究.